Develop, test, and validate a standardized, reproducible spinal cord injury model in animals that is characterized in terms of the evolution of behavioral (functional), electrophysiological, and morphological changes arising as a result of the lesion with the primary intent of testing new therapeutic modalities for the treatment of spinal cord injury. Demonstrate that such a model can be used for testing of new therapeutic approaches by utilizing it for evaluating medical therapies reputed to be useful in the treatment of spinal cord injury. In the first phase of the project, we propose to determine the optimal impact conditions to establish three levels of injury (corresponding to 10%, 50%, and 90% residual functional deficit) using a weight droping device (open impact injury) in the rat.